1、 Copyright 2010 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 Approved November 12, 2010 Table of Contents Page Foreword . 2 Intellectual Property 2 1 Scope . 3 2 Conformance Notation . 3 3 Normative Reference . 3 4 Channel Code 4 5
2、Signal Levels and Specifications . 4 6 Transmission Order 6 7 Connector and Cable Types 6 Annex A Biphase Code Characteristics (Informative) 7 Annex B Waveform Measurement Method (Informative) . 8 Annex C Signal Specifications (Informative) 9 Annex D Jitter Template (Normative) . 10 Annex E Bibliogr
3、aphy (Informative) . 11 Revision Notes 12 Page 1 of 12 pages SMPTE ST 310:2010 Revision of SMPTE 310M-2004 SMPTE STANDARD for Television Synchronous Serial Interface for MPEG-2 Digital Transport Stream SMPTE ST 310:2010 Page 2 of 12 pages Foreword SMPTE (the Society of Motion Picture and Television
4、Engineers) is an internationally-recognized standards developing organization. Headquartered and incorporated in the United States of America, SMPTE has members in over 80 countries on six continents. SMPTEs Engineering Documents, including Standards, Recommended Practices, and Engineering Guideline
5、s, are prepared by SMPTEs Technology Committees. Participation in these Committees is open to all with a bona fide interest in their work. SMPTE cooperates closely with other standards-developing organizations, including ISO, IEC and ITU. SMPTE Engineering Documents are drafted in accordance with th
6、e rules given in Part XIII of its Administrative Practices. SMPTE ST 310 was prepared by Technology Committee 32NF. Intellectual Property At the time of publication no notice had been received by SMPTE claiming patent rights essential to the implementation of this Standard. However, attention is dra
7、wn to the possibility that some of the elements of this document may be the subject of patent rights. SMPTE shall not be held responsible for identifying any or all such patent rights. SMPTE ST 310:2010 Page 3 of 12 pages 1 Scope This standard describes the physical interface and modulation characte
8、ristics for a synchronous serial interface to carry MPEG-2 transport bit streams at rates up to 40 Mb/s. It is a point-to-point interface intended for use in a low-noise environment. The low-noise environment is defined as a noise level that would corrupt no more than one MPEG-2 data packet per day
9、at the transport clock rate. When other transmission systems (e.g., studio-to-transmitter microwave links, etc.) are interposed between devices employing this interface, higher noise levels may be encountered. In such cases, it is recommended that appropriate error correcting methods be used (see Fi
10、gure 1). 2 Conformance Notation Normative text is text that describes elements of the design that are indispensable or contains the conformance language keywords: “shall“, “should“, or “may“. Informative text is text that is potentially helpful to the user, but not indispensable, and can be removed,
11、 changed, or added editorially without affecting interoperability. Informative text does not contain any conformance keywords. All text in this document is, by default, normative, except: the Introduction, any section explicitly labeled as “Informative“ or individual paragraphs that start with “Note
12、:” The keywords “shall“ and “shall not“ indicate requirements strictly to be followed in order to conform to the document and from which no deviation is permitted. The keywords, “should“ and “should not“ indicate that, among several possibilities, one is recommended as particularly suitable, without
13、 mentioning or excluding others; or that a certain course of action is preferred but not necessarily required; or that (in the negative form) a certain possibility or course of action is deprecated but not prohibited. The keywords “may“ and “need not“ indicate courses of action permissible within th
14、e limits of the document. The keyword “reserved” indicates a provision that is not defined at this time, shall not be used, and may be defined in the future. The keyword “forbidden” indicates “reserved” and in addition indicates that the provision will never be defined in the future. A conformant im
15、plementation according to this document is one that includes all mandatory provisions (“shall“) and, if implemented, all recommended provisions (“should“) as described. A conformant implementation need not implement optional provisions (“may“) and need not implement them as described. Unless otherwi
16、se specified, the order of precedence of the types of normative information in this document shall be as follows: Normative prose shall be the authoritative definition; Tables shall be next; followed by formal languages; then figures; and then any other language forms. 3 Normative Reference The foll
17、owing standard contains provisions which, through reference in this text, constitute provisions of this standard. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the pos
18、sibility of applying the most recent edition of the standards indicated below. IEC 61169-8 (2007-02), Part 8: Sectional Specification R.F. Coaxial Connectors with Inner Diameter of Outer Conductor 6,5 mm (0,256 in) with Bayonet Lock Characteristic Impedance 50 (Type BNC), Annex A (Normative) Informa
19、tion for Interface Dimensions of 75 Characteristic Impedance Connector with Unspecified Reflection Factor11Please note that the title of this normative reference can be misleading. This standard requires the use of the 75-ohm connector defined in this reference. SMPTE ST 310:2010 Page 4 of 12 pages
20、4 Channel Code 4.1 Biphase-mark coding shall be used (see Figure 2). 4.2 The encoding rules are as follows: A transition always occurs at the beginning of the bit whatever its value is (0 or 1). For logical 1, a transition occurs in the middle of the bit. For logical 0, there is no transition in the
21、 middle of the bit. 4.3 See annex A for biphase code properties. 5 Signal Levels and Specifications 5.1 The output of the generator or signal source shall be measured across a 75-ohm resistive load connected through a short coaxial cable. Figure 3 depicts the measurement dimensions for amplitude, ri
22、se time, and overshoot (see Annex B for the preferred measurement method.) Figure 1 Example of possible interface use Transport multiplex transmitter input SMPTE ST 310:2010 Page 5 of 12 pages Figure 2 Biphase mark coding scheme Figure 3 Waveform measurement dimensions 5.1.1 The generator or signal
23、source shall have an unbalanced output circuit with a source impedance of 75 ohms and a return loss of at least 30 dB over a frequency range from 100 kHz to the interface clock frequency. 5.1.2 The peak-to-peak signal amplitude shall be 800 mV 10%. 5.2 The dc offset as defined by the amplitude midpo
24、int of the signal shall be nominally 0.0 V 0.5 V. 5.3 The rise and fall times determined between the 20% and 80% amplitude points shall be no less than 0.4 ns and no greater than 5.0 ns and shall not differ by more than 1.6 ns. 5.4 Overshoot of the rising and falling edges of the waveform shall not
25、exceed 10% of the amplitude. 5.5 The interface clock jitter, drift, and wander requirements are specified in both the frequency and time domain. Drift and wander in 5.5.1 are specified in the frequency domain, below 1 Hz. The 1-Hz limit prevents the drift rate specification from imposing jitter limi
26、ts tighter than those described in 5.5.2. Jitter timing error in 5.5.2 is specified in the time domain. Both 5.5.1 and 5.5.2 are presented in table form in Annex C. SMPTE ST 310:2010 Page 6 of 12 pages 5.5.1 The interface clock frequency error (drift limit) shall not exceed 2.8 ppm. The rate of freq
27、uency change (drift rate) shall not exceed 0.028 ppm/s. These two measurements should ignore timing error terms occurring at a 1-Hz or higher rate. 5.5.2 The jitter in the timing of the interface signal transitions shall not exceed 2 ns p-p, measured over a bandwidth of 1 Hz to 1/100 of the interfac
28、e clock frequency. 5.5.3 The specifications of 5.5.1 and 5.5.2 are combined in Annex D and formed into a template showing the maximum jitter allowed. Note: This specification follows the general method described in SMPTE RP 184 with two exceptions: 1) the specification extends below 10 Hz and 2) the
29、 jitter value is specified in seconds rather than unit intervals. Using SMPTE RP 184 nomenclature, f1 = 1 Hz, f4 = (1/100 fclk), UI = 2 ns. 6 Transmission Order The MSB of any data word shall be transmitted first. 7 Connector and Cable Types 7.1 The connector shall have mechanical characteristics co
30、nforming to the 50-ohm BNC type. Mechanical dimensions of the connector may produce either a nominal 50-ohm or a nominal 75-ohm impedance and shall be usable at frequencies up to 850 MHz. However, the electrical characteristics of the connector and its associated interface circuitry shall provide a
31、resistive impedance of 75 ohms. Where a 75-ohm connector is used, its mechanical characteristics must reliably interface with the nominal 50-ohm BNC type defined by IEC 61169-8. 7.2 Applications of this standard do not require a particular type of coax. It is_necessary for the frequency response of
32、the coax loss, in decibels, to be approximately proportional to 1/f from 1 MHz to the interface clock frequency of the signal being transmitted to ensure correct operation of automatic cable equalizers over moderate to maximum lengths. 7.3 A receiver shall operate with up to 3-dB amplitude loss at h
33、alf the interface clock frequency. SMPTE ST 310:2010 Page 7 of 12 pages Annex A (Informative) Biphase Code Characteristics Three properties of biphase-mark coding are: 1) The interface clock frequency is twice that of the transport clock. 2) No dc component in the spectrum (see Figure A.1). 3) A car
34、rier is always present, even for continuous data of ones or zeros. Consider two ATSC data streams encoded using the coding method described in 4.2: Case 1. When all zeros are sent, the encoding rules are: A transition always occurs at the beginning of the bit whatever its value (0 or 1). For logical
35、 0, there is no transition in the middle of the bit. Case 1 would create a continuous 9.69-MHz clock. Case 2. When all ones are sent, the encoding rules are: A transition always occurs at the beginning of the bit whatever its value (0 or 1). For logical 1, a transition occurs in the middle of the bi
36、t. Case 2 would create a continuous 19.39-MHz clock. Figure A.1 Spectral density biphase code SMPTE ST 310:2010 Page 8 of 12 pages Annex B (Informative) Waveform Measurement Method The preferred method for measuring serial digital waveform amplitude, rise time, and overshoot is using a 1-GHz bandwid
37、th oscilloscope. Input impedance of the oscilloscope should be 75 ohms with a return loss greater than 20 dB to 400 MHz. Measurements should be made using a coaxial cable between the transmitter and oscilloscope with no more than 0.15 dB loss at the interface clock frequency. SMPTE ST 310:2010 Page
38、9 of 12 pages Annex C (Informative) Signal Specifications ATSC modulator symbol clock (Fsym) is defined as: Fsym = 4.5E6 x (684/286) = 10,762,237.76 Hz. The ratio of modulator symbol clock to 8-VSB transport clock is defined as: 313 Ftp = 564 Fsym, which produces 8-VSB transport stream of 19,392,658
39、.46 bits/s and a transport clock of 19,392,658.46 Hz. The ratio of modulator symbol clock to 16-VSB transport clock is defined as: 313 Ftp = 1128 Fsym, which produces 16-VSB transport stream of 38,785,316.92 bits/s and a transport clock of 38,785,316.92 Hz (see Table C.1). Table C.1 Clock rates and
40、related specifications Signal Clock frequency 2.8 ppm drift limit 0.028 ppm drift rate Jitter measurement upper frequency limit (f4) Symbol clock 10.76 . MHz 30 Hz 0.30 Hz/s 110 kHz 8-VSB transport stream 19.39 . MHz 54 Hz 0.54 Hz/s 190 kHz 16-VSB transport stream 38.78 . MHz 108 Hz 1.10 Hz/s 390 kH
41、z SMPTE ST 310:2010 Page 10 of 12 pages Annex D (Normative) Jitter Template The jitter and wander requirements in 5.5 can be described with a template showing the maximum timing error allowed as a function of frequency (see Figure D.1). Figure D.1 Jitter template SMPTE ST 310:2010 Page 11 of 12 page
42、s Annex E (Informative) Bibliography ATSC A/53, ATSC Digital Television Standard, Part 2:2007, RF/Transmission System Characteristics ATSC A/53, ATSC Digital Television Standard, Part 3: 2009, Service Multiplex and Transport Subsystem Characteristics ATSC A/64B (May 2008), Transmission Measurement a
43、nd Compliance for Digital Television ISO/IEC 13818-1:2007, Information Technology Generic Coding of Moving Pictures and Associated Audio Information: Systems SMPTE RP 184-2004, Specification of Jitter in Bit-Serial Digital Systems SMPTE ST 310:2010 Page 12 of 12 pages Revision Notes This revision in
44、corporates Amendment #1 to SMPTE ST 310. The changes are summarized below: 1. The following Sections have been added to be in conformance with other SMPTE documents: Table of Contents, Foreword, and Intellectual Property. 2. Section 2, Conformance Notation has been added and all sections following have been renumbered (including all references to sections within the document). 3. Section 3, Normative References has been updated. 4. Annex E, Bibliography has been updated.
